Synthesis of acid anhydride‐modified flexible epoxy resins and enhancement of impact resistance in the epoxy composites

Abstract

Epoxy resins are key materials used in various applications, including coatings, adhesives, and composites. Tougheners, such as nanoparticles, soft polymers, elastomeric polyurethanes, and core/shell particles, have been widely applied to compensate for the brittleness of the epoxy matrix and to enhance the impact resistance. Modifying epoxy resin by reacting it with a flexible component is one of the representative methods to overcome the weakness of cured epoxy polymers upon impact. For introducing flexible parts, we synthesized three types of epoxy-modified resins by reacting acid anhydride with glycidol, followed by reaction with bisphenol [F, S, or J] glycidyl ether to produce flexible modified epoxy resins. Mechanical tests, such as flexural strength and impact resistance tests, were performed by adding various amounts of the synthesized resin to the epoxy composites. The results of these tests suggest that the modified resins were effective in improving the toughness of the epoxy matrix.

Effects of fatty acid modified epoxy resin on long‐chain epoxy and its physical properties

“…Then, bisphenol F epoxy (519.3 g, 0.94 mol), or JER-320 epoxy (826.7 g, 0.94 mol) was added. 17 The reaction was halted when the EEVs reached 277.13 g/eq (AMER-F) or 441.14 g/eq (AMER-J).…”

“…[14][15][16] Previously, we reported the synthesis of acid anhydride-modified epoxy resins (AMERs) to compensate for the brittleness of epoxy polymers. 17 Although both AMER-F and AMER-J showed good mechanical properties improvement in flexural and impact strength with 10 mol% addition, it is expected that it will be difficult to find a suitable content for the application as the properties rapidly decrease as the content increases. Dimeric fatty acids reported to be useful in epoxy coatings, flexographic printing inks or hotmelt adhesives 18 have good mechanical properties and convenient to obtain.…”

Influence patterns of shear-thickening gel on overload transmission: a numerical simulation study

“…Currently, materials commonly used for fuzes' cushioning and damping include polyurethane [1,2] , epoxy resin [3,4] , natural rubber [5,6] , and more. Shear-thickening gel (STG) is a non-Newtonian fluid, when subjected to impact, STG undergoes a liquid-to-solid transition, resulting in a significant increase in its storage modulus.…”